Question : The MAPI provider failed

The MAPI call 'OpenMsgStore' failed with the following error:
The attempt to log on to the Microsoft Exchange Server computer has failed.
The MAPI provider failed.
Microsoft Exchange Server Information Store
ID no: 8004011d-0512-00000000

Answer : The MAPI provider failed

APART from removing the log files you have to remove the checkpoint file from the drive also to generate a new file without any referenes to the old logs .
You have to remove the .chk file
THANKS